The present invention relates to the positioning of a workpiece in a vise for machining, and more particularly to an improved clip system for holding parallel plates against respective jaws of the vise in proper position to mount the workpiece during machining.
A vise is commonly used to secure a workpiece intended to be machined. Typically, the workpiece is mounted within the opposite jaws of the vise and secured in proper position therebetween using a pair of flat, metal plates known as parallels. These parallels, which may be of varying widths and thicknesses, are mounted immediately adjacent to the respective jaws in substantially identical positions on either side of the vise so that their upper margins act as reference surfaces for the mounting of the workpiece between the vise jaws. The parallels thus serve to mount the workpiece in an exact attitude while machining and it is essential that the parallels be held securely in place against the jaws in order for the workpiece to be machined correctly.
In the past, a number of different devices have been used to hold the parallels against the jaw surfaces. For instance, spring members have been inserted in the space between the parallels in pressing engagement with the parallels themselves with the springs being under compression. While these spring members have effectively served to position the parallels pressed against the vise jaws they can become easily dislodged under working conditions and hurdle through space, risking bodily injury to a workman adjacent to the workpiece. Other, more elaborate systems have been used but these have been expensive to produce and complex to use, and they require considerable amount of space for use in holding the parallels in place. Some of these more elaborate prior art holding systems have required substantial modifications to the standard jaws of a machine vise in order to implement their use and operation, and in many cases, the costs and effort to adapt those holding systems to existing vises has been burdensome. Furthermore, most of these existing systems have been devised and developed for disposition and operation within the spatial confines between the opposed vise jaws. As a result, these existing holding systems may sometimes interfere with the positioning of the workpiece between the jaws and disrupt its proper attitude for machining. A need therefore exists for an improved parallel holding system that works safely and effectively without interfering with the position of the workpiece while machining, and that can easily adapt to existing machine vises.